Apple has bought the CUPS code base, and has hired it's lead developer. "CUPS was written by Michael R Sweet, an owner of Easy Software Products. In February of 2007 Apple Inc. hired Michael and acquired ownership the CUPS source code. While Michael is primarily working on non-CUPS projects, he will continue to develop and support CUPS, which is still being released under the existing GPL2/LGPL2 licensing terms."

And the reply has been the same, LLVM is a replacement for GCC which allows Apple to inject proprietary code into or replace GCC completely, as the license is more in line with what Apple want which is take and not give back.